Review



231



Weight is at a miimmum in fall; increases from December to

maximum in January ; decreasing to standard weight in April.


Spring migration is in an early (late February) flight, and a distinct

one later. Some birds consistently arrive early or late ; some vary.

Warmth has a strong influence on arrival dates of earlies, but it takes

marked cold to delay the lates. Young hens arrive late their first

spring, but do better in following years.


The ceremonial proclamation of territorial rights, in which song

plays the chief part, does not occur in years with a depleted population.

Young males warble continuously, but on staking a claim assume the

adult song at once and never warble again. Singing in January and

February is correlated to temperature but not sunshine. Maps of the

district show the same males holding the same territory from year to

year, or closely adjoining. Females return to the same territory or

settle close by. Maps show young males and females returning to within

an average 280 and 270 metres of their birthplace ; of interest to

fauna-preservers. There are maps of nesting sites for several generations.


Cocks arriving late retake their territories from any first year

residents that have settled on them. Late hens usually find the old

place occupied, but there are always mateless cocks. They are said to

pay no attention to beauty in plumage or song, easily discernible in

their degree, in the male ; or even desirability of residence. Beauty and

melody are prerogative of the cock Sparrow. Cocks make bigamous

advances about their boundaries, but they only make the hens furious:

unless mischance has befallen their mates a young cock may fail to

establish himself his first spring but return next year and succeed.

A young hen builds her first nest as efficiently as her last. The ages

are given of seven birds on laying their first egg. The start of egg

laying depends on temperature alone.


And much more—weights and numbers of eggs in successive

clutches—percentages of hatching and of fully fledged young

population problems—but this first volume is only a breaking of the

ground—a rough sketch of the Song Sparrow ; detail is to follow in a

second volume. May it be bound in a permanent cover.



